title: Octreotide-induced long QT syndrome in a child with congenital hyperinsulinemia and a novel missense mutation (p.Met115Val) in the ABCC8 gene.
abstract: OBJECTIVE
  Congenital hyperinsulinism (CHI) denotes an inappropriate secretion of insulin from pancreatic β-cells in the presence of a low blood glucose level due to various genetic causes. Diazoxide is the first-line medical treatment for CHI. In case of failure, a somatostatin analogue called octreotide is used. A prolonged QT interval is an unusual side effect of octreotide which can be lethal if unrecognized.
  
  
  METHODS
  We report on a 35-day-old infant who was diagnosed with CHI on the 3rd day of his life and underwent pancreatectomy due to failure of medical treatment at 8 months. His genetic analysis revealed a compound heterozygosity for a novel missense mutation (p.Met115Val) and a nonsense mutation (p.Trp1339X) in the ABCC8 gene. Furthermore, at the 6th month of follow-up, a long QT (0.49 s) was determined by ECG examination, which was normalized following discontinuation of octreotide treatment after pancreatectomy. Thus, the long QT was considered to be secondary to octreotide medication.
  
  
  CONCLUSIONS
  We recommend ECG monitoring before and during octreotide treatment in order to recognize a prolonged QT interval and to prevent related complications in cases with congenital hyperinsulinemia.
authors.affiliation: Department of Pediatric Endocrinology, Gazi University, Ankara, Turkey.
authors.forename: Nurullah
authors.initials: N
authors.lastname: Celik
authors.forename: Peyami
authors.initials: P
authors.lastname: Cinaz
authors.forename: Hamdi Cihan
authors.initials: HC
authors.lastname: Emeksiz
authors.forename: Khalid
authors.initials: K
authors.lastname: Hussain
authors.forename: Orhun
authors.initials: O
authors.lastname: Çamurdan
authors.forename: Aysun
authors.initials: A
authors.lastname: Bideci
authors.forename: Esra
authors.initials: E
authors.lastname: Döğer
authors.forename: Özge
authors.initials: Ö
authors.lastname: Yüce
authors.forename: Zafer
authors.initials: Z
authors.lastname: Türkyılmaz
authors.forename: Ayşe Deniz
authors.initials: AD
authors.lastname: Oğuz
mesh_terms: D019943:Amino Acid Substitution; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000009:adverse effects*; D044903:Congenital Hyperinsulinism / Q000188:drug therapy / Q000235:genetics; D006801:Humans; D007223:Infant; D008133:Long QT Syndrome / Q000139:chemically induced / Q000235:genetics; D008297:Male; D020125:Mutation, Missense; D015282:Octreotide / Q000008:administration & dosage / Q000009:adverse effects*; D064233:Sulfonylurea Receptors / Q000235:genetics*
chemical_list: C577507:ABCC8 protein, human; D018931:Antineoplastic Agents, Hormonal; D064233:Sulfonylurea Receptors; D015282:Octreotide